Article
Activities of artesunate‑based combinations and tafenoquine against Babesia bovis in vitro and Babesia microti in vivo
Registro en:
CARVALHO, Leonardo J. M. et al. Activities of artesunate‑based combinations and tafenoquine against Babesia bovis in vitro and Babesia microti in vivo. Parasites & Vectors, v. 13, n. 362, p. 1-9, 2020.
1756-3305
10.1186/s13071-020-04235-7
Autor
Carvalho, Leonardo J. M.
Tuvshintulga, Bunduurem
Nugraha, Arifin B.
Sivakumar, Thillaiampalam Sivakumar
Yokoyama, Naoaki
Resumen
Background: Babesiosis represents a veterinary and medical threat, with a need for novel drugs. Artemisinin-based
combination therapies (ACT) have been successfully implemented for malaria, a human disease caused by related
parasites, Plasmodium spp. The aim of this study was to investigate whether ACT is active against Babesia in vitro and
in vivo.
Methods: Mefloquine, tafenoquine, primaquine, methylene blue and lumefantrine, alone or in combination with
artesunate, were tested in vitro against Babesia bovis. Parasite growth was verified using a SYBR green I-based fluorescence
assay. Mice infected with Babesia microti were treated with mefloquine or tafenoquine, alone or in combination
with artesunate, and parasitemia was verified by microscopy and PCR.
Results: All drugs, except lumefantrine, showed in vitro activity against B. bovis, with methylene blue showing the
most potent activity (concentration 0.2 μM). Combination with artesunate led to improved activity, with mefloquine
showing a striking 20-fold increase in activity. Tafenoquine (10 mg/kg, base), combined or not with artesunate, but
not mefloquine, induced rapid clearance of B. microti in vivo by microscopy, but mice remained PCR-positive. Blood
from mice treated with tafenoquine alone, but not with tafenoquine-artesunate, was infective for naive mice upon
sub-inoculation.
Conclusions: Tafenoquine, and most likely other 8-aminoquinoline compounds, are promising compounds for the
development of ACT for babesiosis.